Cutting instruments have been used for centuries by craftsmen, hunters, and others requiring a sharp cutting instrument. More recently, fixed length knives have been replaced with popular folding knives, including bi-fold knives, which generally have two positions. In a first extended position of use, the knife cutting blade is extended to expose the blade cutting edge and permit cutting therein. In a second closed position, the cutting edge of the blade is stored within a cavity or recess in the handle portion of the knife, thus preventing the blade from being exposed. The folding mechanism further provides a cutting instrument which is much shorter in length than a typical fixed blade knife. As discussed herein, the term “bi-fold” refers to a folding knife where the blade rotates at a hinge point on the handle and is positioned adjacent to the handle portion as depicted herein in the drawings. Although these types of knives are extremely convenient, they can potentially become dangerous if the cutting blade does not have a locking mechanism to securely keep the knife blade in the first extended position of use. Likewise, it is often convenient to have a locking mechanism or some form of frictional ball détente apparatus to prevent the knife from inadvertently opening when the knife blade is in the second closed position.
Although there are other types of locking mechanisms used to prevent the inadvertent closure of a folding knife blade, none are simplistic to use, inexpensive to manufacture and are essentially fail-proof. Thus, there is a need for a type of bi-fold folding knife locking mechanism which is simplistic to use, inexpensive to manufacture, and provides substantial strength to prevent any inadvertent failure.